Digital adoption has become a defining challenge and opportunity in public sector reform, particularly as governments integrate emerging technologies such as artificial intelligence, cloud computing, and big data into service delivery. In this context, electronic government (e-Government) has emerged as a central pillar of digital transformation, aiming to improve efficiency, transparency, and citizen engagement. However, the adoption of e-Government services remains inconsistent, especially in developing countries, where infrastructural, institutional, and socio-cultural barriers hinder widespread uptake. This study investigates the determinants of digital adoption in public services by examining e-Government usage in Indonesia, a representative developing country. Extending the Unified Theory of Acceptance and Use of Technology (UTAUT), the study incorporates two endogenous and four exogenous context-specific factors tailored to emerging digital environments. Using survey data from 314 e-Government users and employing structural equation modelling (SEM), the study evaluates the relative influence of these factors on adoption outcomes. The results contribute to a deeper theoretical understanding of digital adoption in the public sector and provide actionable insights for policymakers seeking to advance inclusive and effective e-Government implementation as part of national digital transformation efforts.